The invention relates to a boring tool, in particular a reamer and a method for surface processing of an inner walling of a pre-drilled core bore of a workpiece.
Such a boring tool is used in vehicle construction for example during production of a cylinder-head bore, namely for fine processing of the inner wall of the cylinder-head bore, which improves the surface quality and the shape and dimensional accuracy of the bore.
From DE 38 05 729 A1 a generic boring and reaming tool is known, which has a clamping shank and a boring body. Between the end face of the boring body and the clamping shank three main blades extend helically along a longitudinal axis of the boring body. Each of these main blades has a blade web, which has a rake face which faces a groove-shaped chip space and a free surface on an outer circumference. The rake face and the free surface converge at a cutting edge which extends along the longitudinal axis of the boring body, and with which material can be removed from the inner walling of a predrilled core bore of a work-piece when the boring tool rotates.
By means of the reamer known from DE 38 05 729 A1 the surface processing of an already predrilled cylinder head core bore is performed as follows: first the reaming tool is brought to a very high rotational speed (for example in the range from 10,000 to 15,000 rpm). Subsequently at this high rotational speed the rotating reaming tool is inserted into and moved out of the cylinder head core bore with an axial movement. Depending on the dimensioning of the cylinder head core bore to be processed, the time required for the surface processing is within a range of for example one second, which especially in the case of large-scale serial production is a relatively long period of time.